Semiautomatic macroencapsulation of large numbers of porcine hepatocytes by coextrusion with a solution of AN69 polymer

We have previously demonstrated that allogenic and xenogenic hepatocytes macroencapsulated manually in AN-69 polymer and transplanted intra-peritoneally in rats remained viable for several weeks. However, this manual technique is inadequate to encapsulate several billions of hepatocytes which would be required to correct hepatic failure in big animals or humans. In the present study, we developed an original semiautomatic device in which isolated pig hepatocytes and the polymer solution containing 6% poly(acrylonitrile-sodium methallylsulfonate), 91% dimethylsulfoxide and 3% 0.9% NaCl solution were coextruded through a double-lumen spinneret. The extruded minitube (inner diameter: 1.8 mm, wall thickness: 0.07–0.1 mm) containing the encapsulated hepatocytes fell and coiled up in a 0.9% NaCl solution at 4°C and was cut down in 4 m units containing about 120 million hepatocytes. This process allowed to encapsulate 50 million hepatocytes by minute with a preserved immediate cell viability (92±5%). To test prolonged cell viability after coextrusion, the minitubes were implanted intraperitoneally in rats. Three and seven days after implantation, they were explanted and analyzed. Cells were viable and well-preserved. Therefore, the semiautomatic device appears able to efficiently macroencapsulate in a limited time several billions of porcine hepatocytes which remain viable after transplantation in xenogenic conditions.